6 ms·

Does this mean that it was much more contagious than thought, if it spreads so fast while so many already have some immunity? Also, if 1/4 of New York City has

Does this mean that it was much more contagious than thought, if it spreads so fast while so many already have some immunity? Also, if 1/4 of New York City has already had covid-19, then maybe there is only ~1/4 left who wouldn't have immunity. Which would imply that if all restrictions were lifted (in NYC) the "curve" of new infections would be much lower than the first one.

fxtentacle 6y ago
I believe this research only shows that their immune system has some sort of defense against covid, but not that they'll be immune.
- joaomacp 6y ago
  Does this explain asymptomatic cases? Maybe people don't develop symptoms because they have cold-related antibodies that don't let COVID develop. Can these people still shed and transmit SARS-CoV-2?
  - fxtentacle 6y ago
    It sadly appears that many people who recover from covid have temporary or permanent (not known yet) lung damage anyway. So those asymptomatic might simply be people whose natural lung operation is strong enough that they can compensate for the covid damage.
- jfnixon 6y ago
  The response was primarily by Th cells, not the TC cells, so yes, this isn't immunity, but it would speed to body's adaptive immune system response. OTOH, the killer feature of Covid-19 seems to be triggering an out-of-control adaptive immune response. That's probably why kids aren't dying, as their adaptive immune response is still developing.
gvb 6y ago
It means that people that have the at least one common antibody from exposure to the common cold as those that have had COVID-19. The implication (in the best of all possible worlds) is that the antibodies that fight common cold also fight COVID-19. Or it could be a simple correlation and not significant.
elmerfud 6y ago
No it doesn't mean that at all. What this is telling you and what media has been avoiding saying is that coronavirus is a family of viruses that make up the common cold. It's not the only virus that's lumped in as the common cold but it is one kind. Coronavirus isn't new, covid19 is just a previously unknown variation. What is paper is saying is that previous exposure to coronavirus (the common cold) grants some level of immunity to covid19.
- CydeWeys 6y ago
  > coronavirus is a family of viruses that make up the common cold Wrong. There are 200+ strains of various viruses that are all lumped together as the "common cold" only 4 of which are coronaviruses. The vast majority of common colds are not coronaviruses.
  - elmerfud 6y ago
    I guess reading is hard when it's longer than a Twitter post because my very next sentence was. > It's not the only virus that's lumped in as the common cold but it is one kind. Perhaps not having knee jerk reactions and careful examination of the information is what's needed.
- antonvs 6y ago
  > What is paper is saying is that previous exposure to coronavirus (the common cold) grants some level of immunity to covid19. It's not saying that. The presence of these antibodies does not necessarily mean any level of immunity against SARS-CoV-2, which is a different virus than the one that triggered these antibodies. The degree to which these antibodies contribute towards immunity against the new virus is unknown, and wasn't evaluated by this study.
alkonaut 6y ago
The effective R is R(0) multiplied by (among other things) the susceptible population. If those with existing protection are still susceptible and still become infectious when infected, then this does't change the evolution. It's likely that those who are infected but have some immunity develops a less severe illness, which is possibly less infectious. But there is something that works in the opposite direction: if those with some protection become asymptomatic or mildly symptomatic but are still spreaders, then their lack of symptoms might mean they move around more and have more contacts, outweighing their smaller level of infectiousness. We can't know. If those with existing protection can't become spreaders, then it should indeed mean that the R0 is much higher than expected (It was estimated from doubling assuming 100% were initially susceptible, so if only 50% were initially susceptible then the estimate would be off by a factor 2). But I don't think that this is what the paper is saying. It's saying that some have partial immunity responses that deal with the infection. They still get immunity after their infection, not before.

fxtentacle 6y ago

I believe this research only shows that their immune system has some sort of defense against covid, but not that they'll be immune.

joaomacp 6y ago
Does this explain asymptomatic cases? Maybe people don't develop symptoms because they have cold-related antibodies that don't let COVID develop. Can these people still shed and transmit SARS-CoV-2?
- fxtentacle 6y ago
  It sadly appears that many people who recover from covid have temporary or permanent (not known yet) lung damage anyway. So those asymptomatic might simply be people whose natural lung operation is strong enough that they can compensate for the covid damage.
jfnixon 6y ago
The response was primarily by Th cells, not the TC cells, so yes, this isn't immunity, but it would speed to body's adaptive immune system response. OTOH, the killer feature of Covid-19 seems to be triggering an out-of-control adaptive immune response. That's probably why kids aren't dying, as their adaptive immune response is still developing.

gvb 6y ago

It means that people that have the at least one common antibody from exposure to the common cold as those that have had COVID-19. The implication (in the best of all possible worlds) is that the antibodies that fight common cold also fight COVID-19. Or it could be a simple correlation and not significant.

elmerfud 6y ago

No it doesn't mean that at all. What this is telling you and what media has been avoiding saying is that coronavirus is a family of viruses that make up the common cold. It's not the only virus that's lumped in as the common cold but it is one kind. Coronavirus isn't new, covid19 is just a previously unknown variation. What is paper is saying is that previous exposure to coronavirus (the common cold) grants some level of immunity to covid19.

CydeWeys 6y ago
> coronavirus is a family of viruses that make up the common cold Wrong. There are 200+ strains of various viruses that are all lumped together as the "common cold" only 4 of which are coronaviruses. The vast majority of common colds are not coronaviruses.
- elmerfud 6y ago
  I guess reading is hard when it's longer than a Twitter post because my very next sentence was. > It's not the only virus that's lumped in as the common cold but it is one kind. Perhaps not having knee jerk reactions and careful examination of the information is what's needed.
antonvs 6y ago
> What is paper is saying is that previous exposure to coronavirus (the common cold) grants some level of immunity to covid19. It's not saying that. The presence of these antibodies does not necessarily mean any level of immunity against SARS-CoV-2, which is a different virus than the one that triggered these antibodies. The degree to which these antibodies contribute towards immunity against the new virus is unknown, and wasn't evaluated by this study.

alkonaut 6y ago

The effective R is R(0) multiplied by (among other things) the susceptible population. If those with existing protection are still susceptible and still become infectious when infected, then this does't change the evolution. It's likely that those who are infected but have some immunity develops a less severe illness, which is possibly less infectious. But there is something that works in the opposite direction: if those with some protection become asymptomatic or mildly symptomatic but are still spreaders, then their lack of symptoms might mean they move around more and have more contacts, outweighing their smaller level of infectiousness. We can't know. If those with existing protection can't become spreaders, then it should indeed mean that the R0 is much higher than expected (It was estimated from doubling assuming 100% were initially susceptible, so if only 50% were initially susceptible then the estimate would be off by a factor 2). But I don't think that this is what the paper is saying. It's saying that some have partial immunity responses that deal with the infection. They still get immunity after their infection, not before.